The subject matter disclosed herein relates to ultrasonic inspection, and more particularly to methods and systems for enhanced ultrasonic inspection, e.g., for ultrasonic inspection of thin materials or coatings on an object, or for enhancing high noise ultrasonic signals.
Ultrasonic testing devices can be used to inspect objects to detect and analyze anomalies in the objects. Such testing can involve placing one or more probes on or near the surface of the test object in order to perform testing of the underlying structure, using ultrasonic acoustic waves.
Generally, an ultrasonic testing system can include an ultrasonic probe for transmitting and receiving ultrasonic acoustic waves to and from a test object, and a probe cable for connecting the ultrasonic probe to an ultrasonic test unit that includes a processor for processing signals and calculating measurements and a display for viewing the test results. In an ultrasonic testing system, electrical pulses are fed from the ultrasonic test unit to an ultrasonic probe where they are transformed into acoustic pulses by one or more ultrasonic transducers (e.g., piezoelectric elements) in the ultrasonic probe. During operation, electrical pulses are applied to the electrodes of one or more ultrasonic transducers, thus generating ultrasonic acoustic waves that are transmitted to the test object to which the probe is coupled either directly on the surface of the test object or, e.g., through water in which the test object is immersed. Conversely, when an ultrasonic acoustic wave is reflected from the test object and contacts the surface of the ultrasonic transducer(s), it causes the transducer(s) to vibrate, generating a voltage that is detected as a receive signal by the ultrasonic test unit. As the ultrasonic acoustic waves pass through the test object, various reflections, or echoes, can occur as the ultrasonic acoustic waves interact with anomalies within the test object.
When inspecting an object comprising a thin material, problems may occur due to multiple echoes received from the back wall of the thin material. In such a case, if the material has a dimension that is near the wavelength of the ultrasonic signal, e.g., within ten wavelengths, the multiple received echo reflections may obscure the received signal in such a way as to prevent measurement. In addition, noisy signals may be collected, which defy conventional analysis techniques. Therefore, a need exists for enhanced ultrasonic inspection techniques.